#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <netinet/in.h>

#define BUF_SIZE 1024
int main(){
    //创建套接字
    int serv_sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
    //将套接字和IP、端口绑定
    struct sockaddr_in serv_addr;
    memset(&serv_addr, 0, sizeof(serv_addr));  //每个字节都用0填充
    serv_addr.sin_family = AF_INET;  //使用IPv4地址
    serv_addr.sin_addr.s_addr = inet_addr("127.0.0.1");  //具体的IP地址
    serv_addr.sin_port = htons(1234);  //端口
    bind(serv_sock, (struct sockaddr*)&serv_addr, sizeof(serv_addr));
    //进入监听状态，等待用户发起请求
    listen(serv_sock, 20);
    //接收客户端请求
    struct sockaddr_in clnt_addr;
    int str_len;
    socklen_t clnt_addr_size = sizeof(clnt_addr);
    char message[BUF_SIZE];
    for(int i = 1;i <= 5;i++)
    {
        printf("ready to accept!\n");
        int clnt_sock = accept(serv_sock, (struct sockaddr*)&clnt_addr, &clnt_addr_size);
        printf("connect client %d\n",i);
        //从客户端read来的字符串存在message种接着又write进区
        while(str_len = read(clnt_sock,message,BUF_SIZE))
        {
            printf("Get message: %s\n",message);
            write(clnt_sock,message,str_len);
            memset(message, 0, sizeof(message));
        }
        close(clnt_sock);
    }
    close(serv_sock);
    return 0;
}